Expanding thyroid testing in high risk newborns: total T3, free T4, TSH and TRAB

摘要 甲状腺功能障碍是新生儿期最常见的疾病之一，可导致永久性甲状腺功能障碍。 认知障碍和其他严重并发症，如果不能迅速发现和治疗。新生儿甲状腺 在国家公共卫生实验室进行的筛查彻底改变了对患有严重 先天性原发性甲状腺功能减退症，这种筛查不能有效地识别其他几种常见的新生儿 可能由早产或母体甲状腺功能亢进引起的甲状腺功能紊乱。的主要障碍 目前，对新生儿进行全面的甲状腺检测包括： 多次检测（>2 mL）、检测周转时间长以及需要重复检测以建立适当的治疗计划。由于缺乏明确的共识指南来识别和治疗早产儿甲状腺功能减退症，这些局限性进一步复杂化。我们建议开发一种新型的数字微流控系统（FINDER），用于使用微升体积的全血对新生儿进行快速、近距离的甲状腺检测。通过这种快速跟踪SBIR机制，我们将开发一个多路复用的检测面板，以测量全血中的总T3，游离T4，促甲状腺激素（TSH）和促甲状腺激素受体抗体（TRAB），预计运行时间不到45分钟。FINDER甲状腺系统将允许临床医生：（a）快速识别患有真正中枢性或原发性甲状腺功能减退症的婴儿;（B）将中枢性甲状腺功能减退症（需要治疗）与更常见的早产儿甲状腺素血症区分开来;（c）对血容量受限的新生儿进行重复甲状腺功能测试;（d）快速识别因母体甲状腺功能亢进症而患有Graves病的新生儿。第一阶段的具体目标包括：1）在数字微流控盒上开发T3、游离T4、TSH和TRAB的自动化免疫测定; 2）对每种测定进行初步分析验证;以及3）证明对丢弃的血清样品进行单独测定的初步可行性。进入II期的关键里程碑将是成功完成所有检测试剂盒上的高可靠性和精密度检测。第二阶段的具体目标是：1）优化试剂盒上干燥和储存的试剂配方; 2）使用全血样本在同一个试剂盒上同时进行多重所有测定，并使用干燥试剂和全血样本进行分析验证;以及3）使用杜克临床实验室的标准参考检测作为比较，对完整的甲状腺检测组进行初步临床验证。在第二阶段结束时，我们将有一个可商业化的产品，用于使用微升体积的全血对高危新生儿进行快速、有效和准确的甲状腺检测。我们将寻求FDA对最终产品的批准，该产品最初将在美国医院的儿科患者中销售，未来的潜在市场将面向可能受益于该平台创新功能的其他患者。

ABSTRACT Thyroid dysfunction is among the most common morbidities of the neonatal period and can result in permanent cognitive disability and other serious complications if not rapidly identified and treated. While newborn thyroid screening in state public health laboratories has revolutionized the identification of children with severe congenital primary hypothyroidism, this screening does not effectively identify several other common neonatal disorders of thyroid function that may result from preterm birth or maternal hyperthyroidism. Major barriers to comprehensive thyroid testing in newborns currently include the relatively large volume of blood needed for multiple tests (>2 mL), long assay turn-around times and a need for repeated testing to establish an appropriate treatment plan. These limitations are further complicated by the lack of clear consensus guidelines for identification and treatment of hypothyroidism in preterm newborns. We propose to develop a novel digital microfluidic system (FINDER) for rapid, near patient thyroid testing in newborns using microliter volumes of whole blood. Through this Fast-Track SBIR mechanism, we will develop a multiplexed panel of assays to measure total T3, free T4, thyroid stimulating hormone (TSH) and thyrotropin receptor antibody (TRAB) in whole blood, with an anticipated run time of less than 45 minutes. The FINDER thyroid system will allow clinicians: to (a) rapidly identify infants with true central or primary hypothyroidism; (b) differentiate central hypothyroidism (which requires treatment) from the more common hypothyroxinemia of prematurity; (c) perform repeated thyroid function testing in blood volume-limited neonates; and (d) rapidly identify neonates with Graves disease as a consequence of maternal hyperthyroidism. Phase I Specific Aims include: 1) develop automated immunoassays for T3, free T4, TSH and TRAB on the digital microfluidic cartridge; 2) perform preliminary analytical validations of each assay; and 3) demonstrate preliminary feasibility of the individual assays on discarded serum samples. The key milestone for progression to Phase II will be the successful completion of all assays on-cartridge with high reliability and precision. Phase II Specific Aims are: 1) optimize reagent formulations for on-cartridge drying and storage; 2) multiplex all assays to perform simultaneously on the same cartridge using whole blood samples and perform analytical validations using dried reagents and whole blood samples; and 3) preliminary clinical validation of the complete thyroid testing panel using standard reference tests at Duke Clinical Laboratory as a comparison. At the conclusion of Phase II, we will have a commercializable product for rapid, efficient and accurate thyroid testing in high-risk newborns using microliter volumes of whole blood. We will seek FDA approval of the final product, which will initially be marketed for use in pediatric patients in U.S. hospitals, with a potential future market towards other patients who may benefit from the innovative features of the platform.